Three position snap-acting toggle switch



July 8, 1969 c. E. SANFORD ET AL 3,454,733

THREE POSITION SNAP-ACTING TOGGLE SWITCH Filed June 21, 1967 Sheet of 5 i -56 MM/AK 58 I NH 2g. .11" 68 58 6O 3'? 48. y 36 4 48 1&4 4

INVENTOR CARLTON E. SANFORD JOHN A. BRAUN ATTORNEY V ($977150 ,4476

y 8, 1969 c. E. SANFORD ET AL 3,454,733

THREE POSITION SNAP-ACTING TOGGLE SWITCH Filed June 21, 1967 Sheet of 5 INVE NTOR FIG. 6 CARLTON E. SANFORD JOHN A. BRAUN I ATTORNEY 7 1 9 un Mme,

' July 8,1969 c. E. SANFORD ETAL 3,454,733

THREE POSITION SNAP-ACTING TOGGLE SWITCH Filed June 21, 1967 Sheet J of 5 1 I/ l a 12 %I 156 32 %;-22 3 86 13 21,20 52 sw/ s4 3o l e 105(23 5 4 VZ; sa- 6 --58 60.. 38 70 n .60 43 42 L48 4+ INVENTOR CARLTON E. SANFORD JOHN A. BRAUN ATTORNEY c. E. SANFORD ET AL 3,454,733

THREE POSITION SNAP ACTING TOGGLE SWITCH Filed June 21, 1967 Sheet 4 of5 FIG.

ENVENTOR CARLTON E. SANFORD JOHN A.BRAUN ATTORNEY Z 7M9 [Zn/K July 8, 1969 c. E. SANFORD ET A THREE POSITION SNAP--ACTING TOGGLE SWITCH Filed June 21, 1967 Sheet 6 of 5 INVENTOR FIG. 5 CARLTON E. SANFORD JOHN A. BRAUN ATTORNEY United States Patent US. Cl. 200-67 9 Claims ABSTRACT OF THE DISCLOSURE A three position toggle switch which establishes equal contact pressures in alternately closing one of three circuits between a common contact and respective additional contacts is shown to have a common contact or terminal in the form of a U-shaped bracket. This bracket has its central portion fixed to a base and has its arms upstanding from the base. Three additional contacts are fixed to the base in spaced relation to each other and to the common bracket contact. A main contact arm has ears on each side of the arm which rest on adjacent ends of the bracket arms to support the contact arm for rocking motion between the upstanding arms of the bracket. An auxiliary contact arm has an end fitted between and pivotably connected to the bracket arms at a location beneath the main contact arm, and means link the main and auxiliary contact arms together so that rocking movement of the main contact arm is accompanied by pivotal motion of the auxiliary contact arm. Each of the contact arms have wiper means engaging the bracket contact for maintaining electrical connection to the bracket. Toggle means engage a central portion of the main contact arm holding the auxiliary arm linked thereto in engagement with a contact fixed on the base for closing a first switch circuit, the toggle means being movable to engage either end of the main contact arm to rock this arm into engagement with another contact fixed on the base for closing either of two alternate circuits and to simultaneously pivot the auxiliary contact arm for opening the first circuit.

In aircraft and aerospace applications Where a large number of controls must be accommodated in as small a space as possible, it is desirable that switches to be employed be very compact and yet be able to fulfill the greatest possible number of functions. It is also desirable that such switches open and close circuits with snapaction to minimize contact arcing and wear; that such switches hold switch contacts firmly together in good electrical engagement when in closed circuit position so that the switches maintain said circuits even under conditions of extreme vibration; that such switches close each switch circuit with minimum bouncing between contacts and with substantially equal contact pressures; and, for many applications, it is desirable that such switches be toggle actuated so that the switches are easily operated with a small operating force and so that by reference to the position of the toggle actuator, the toggle means gives visual indication of switch condition.

It is an object of this invention to provide a novel and improved toggle switch; to provide such a switch which is adapted to close any one of three alternate circuits between a common contact or terminal and respective additional contacts; to provide such a switch in which switch contacts are held together with substantially equal pressure for closing any one of said alternate circuits; to provide such a switch in which switch contacts are brought together or moved apart with snap-action for closing and opening switch circuits with minimum contact bounce and with minimum contact arcing and wear; to provide such a switch in which all switch contacts are brought Patented July 8, 1969 "ice together with wiping action to assure good electrical engagement between the contacts; to provide such a switch in which each pair of contacts have substantially equal gap or sharing in open circuit position; to provide such a switch in which a single spring means serves to load each pair of contacts in closing each switch circuit and assures proper sequential opening and closing of switch circuits; and to provide such a switch which is of simple, rugged, compact and inexpensive construction.

Briefly described, the toggle switch of this invention includes an electrically insulating base having a U-shaped bracket of electrically conductive material forming a common switch contact, this bracket having its central portion secured to the base and having its arms upstanding from the base. Three additional contacts are fixed to the base in spaced relation to each other and to the common bracket contact. Preferably terminal means electrically connected to each of these switch contacts are arranged to be accessible from outside the switch of this invention. An electrically conductive main contact arm means has a contact resiliently mounted at each end of the arm and has a pair of ears at each side of the arm, these cars being rested on the ends of the upstanding arms of the common U-shaped bracket to support the main contact arm for rocking motion between the bracket arms. An electrically conductive auxiliary contact arm means has one end fitted between and pivotably connected to the upstanding arms of the U-shaped bracket beneath the main contact arm and a switch contact is resiliently mounted on the distal end of the auxiliary contact arm means. Means link the main and auxiliary contact arms together for common movement so that rocking motion of the main contact arm is accompanied by pivotal motion of the auxiliary contact arm. Each of the contact arms has wiper means engaged with the common bracket contact for maintaining good electrical connection between the bracket contact and the contact arms in all positions of movement of the contact arms. A toggle means pivotably mounted on the base, preferably at a pivot point located above the main contact arm means, is arranged to resiliently engage the central portion of the main contact arm means for holding the auxiliary contact arm means, linked thereto in a position such that the contact at the distal end of the auxiliary arm firmly engages one of the additional contacts fixed to the base, thereby to close a first switch circuit between the common contact and the additional base contact. This toggle means is movable to engage either end portion of the main contact arm means to rock this contact arm so that one of the contacts thereon engages another of the additional contacts fixed to the base for closing an alternative switch circuit, this rocking of the main contact arm serving to pivot the auxiliary contact arm means for simultaneously opening the first switch circuit. Preferably the central portion of the main contact arm means forms a depression so that movement of the toggle means into and out of resilient engagement with said central portion of the main contact arm rocks the arm sharply for opening and closing switch contacts with snap-action.

In this construction, the switch of this invention is adapted to close any one of three alternate circuits between a common contact and respective additional contacts. Further, each of the switch circuits is opened and closed with snap-action, the resiliently mounted switch contacts are brought together with minimum contact bounce and with wiping action to assure good electrical engagement therebetween, the switch contacts are held firmly together with substantially equal contact pressure in closing each switch circuit, and yet the switch is of simple, rugged compact and inexpensive construction.

Other objects, advantages and details of construction of the switch of this invention appear in the following detailed description of a preferred embodiment of the invention, the detailed description referring to the drawings in which:

FIG. 1 is a side elevation view of the switch of this invention showing the switch casing cut away;

FIG. 2 is a section view along line 2-2 of FIG. 1; FIG. 3 is a section view along line 33 of FIG. 2; FIG. 4 is a section view along line 4-4 of FIG. 3; FIG. 5 is a view similar to FIG. 3 showing the switch of this invention in an alternate switch position; and

FIG. 6 is a partial view similar to FIG. 4 illustrating an alternate embodiment of the invention. Referring to the drawings, 10 in FIGS. 1-5 indicates the novel and improved toggle switch of this invention which is shown to include two separate poles mounted in a common base or housing 12, the separate poles preferably being enclosed in separate housing compartments 14 and 16 to be actuated by a common toggle means 18. The toggle switch could be embodied in a single pole device or in other multipole devices within the scope of this invention. In describing the toggle switch, corresponding elements of each pole of the illustrated switch embodiment are identified by the same reference numerals.

As illustrated, the switch 10 includes a base or housing 12 which preferably includes an electrically insulating liner 20 of ceramic material, phenolic resin or other suitably rigid insulating material. This liner is enclosed within a protective outer casing 22 of steel or other metal and has a steel or other metallic cover 24 welded or otherwise secured to the casing in conventional manner. A weld between the cover and easing serves to seal the upper part of the switch housing as will be understood.

In accordance with this invention, a common U-shaped bracket contact or terminal 26, preferably formed of silver-plated cold rolled steel or other suitably rigid material of high electrical conductivity has its base portion 28 fixed to the base 30 of the insulating housing liner 20 and has its arms 32 and 34 upstanding from the base as shown. Terminal means 36 accessible from outside the switch housing 12 is electrically connected to the common contact 26. For example, an insulating bushing 38 of phenolic resin or the like is aligned with an aperture on the liner base 30 and a stud 40 of electrically conductive metal or the like is fitted through the bushing and the liner aperture, the stud having a flange 42 engaging one end of the bushing 38 and having a staked or riveted end 44 secured to the central portion of the common bracket contact. A terminal screw 46 and washer 48 are preferably threadedly attached to the stud 40 for facilitating attachment of leads to the terminal stud.

Three additional contacts 50, 52 and 54 are fixedly mounted to the liner baase 30 in spaced relation to each other and to the common bracket contact 26. In a preferred construction, for example, the contacts 52 and 54 are formed of a silver oxide alloy or other material of high conductivity and are Welded, soldered or otherwise secured to the ends of terminal studs 56. Each of these studs extends through an insulating bushing 58 and an aligned aperture in the liner base 30 and is secured within the bushing and base aperture in any conventional manner, the studs each having a flange 60 abutting one end of the bushing 58 and having a terminal screw 46 and washer 48 attached thereto. The contact 50 is formed of the same material as the contacts 52 and 54 but is preferably welded, soldered or otherwise secured to a bar 67 of electrically conductive material, this bar extending to a terminal stud 64 where it is secured to this terminal stud by a staked or riveted end 66 of the stud. This terminal stud (see FIG. 4) extends through an aperture in the liner base 30 and through an insulating bushing 68 and has a flange 70 abutting one end of the bushing as shown. A terminal screw 46 and washer 48 are also threadedly secured to the terminal stud 64. This arrangement of the contact 50 permits accommodation of the contact within a more compactly shaped switch housing 12. However, the contact 50 could be directly connected to a terminal stud in the manner of contacts 52 and 54 within the scope of this invention.

Although the line-r 20, the bushings 38, 58 and 68, and the studs 40, 56 and 64 may be mounted in the switch 10 as shown, it will be understood that the casing 22 could completely enclose the liner 20 and the terminal studs 40, 56 and 64 could extend through the casing in insulated but hermetically sealed relation to the casing for hermetically sealing the switch 10.

In accordance with this invention, the upstanding arms 32 and 34 of the common bracket contact 26 each preferably terminate in a pair of sloping shoulders 70 separated by a central spacer portion 72 to form a saddle for receiving a main contact arm means 74. The main contact arm means preferably comprises a strip 76 of resilient electrically conductive material such as beryllium copper having movable contacts 78 and 80 secured to opposite ends of the resilient strip. These contacts are preferably formed of the same material as the contacts 50, 52 and 54 and are riveted to the resilient strip 76 as shown. However the contacts could be welded or otherwise secured in electrically conductive relation to the strip 76 within the scope of this invention. A rigid contact arm member 82 is then fixedly secured to the resilient strip in any conventional manner, this rigid member preferably having a definite shape as shown so that the central portion 84 of the contact arm forms a slight depression and so that portions 86 and 88 near the ends of the contact arm are angularly disposed with respect to the central portion of the contact arm. This rigid member 82 preferably has a pair of ears 90 on each side of the contact arm, these ears being rested on respective sloping shoulders 70 on the ends of upstanding arms 32 and 34 of the common bracket contact. In this way, the main contact arm is supported on the ends of the bracket arms for rocking motion of the main contact arm between the up standing arms 32 and 34. The spacer portions 22 on the ends of the bracket arms 32 and 34 engage the ears 90 to locate the main contact arm 74 with respect to the bracket 26 and to restrict longitudinal movement of the arm on the bracket. In a preferred construction, an electrically conductive member 92 is secured to the resilient member 76, for example "by welding or by being riveted to the resilient member 76 by the contact 80 as shown. This electrically conductive member has wiper arms 94 bent outwarly from the member to make firm resilient sliding engagement with the arms 32 and 34 of the common bracket 26, thereby to maintain good electrical contact between the common bracket and the resilient strip 76 of the main contact arm in all positions of rocking movement of main contact arm. Preferably the rigid member 82 of the main contact arm is notched at 93 to provide clearance for the wiper arms 94. An additional member 96 forming a loop 98 is also attached to the main contact arm.

In a preferred construction, the member 96 is attached to the rigid arm member 82 and to the resilient arm member 76 by projection Welds 99 as illustrated particularly in FIG. 3. That is, these projection welds are formed between the rigid and more weldable members 82 and 96 and fit through apertures in the resilient member 76 for trapping or locking the resilient member between the rigid members.

In accordance with this invention, an auxiliary contact arm means 100 embodies a rigid member 102 which is secured to a resilient electrically conductive member 104 preferably by projection welding the member 102 to a plate 105 located on the opposite side of the resilient member 104 as shown in FIG. 3. The conductive member 104 has a pair of wiper arms 106 at one end bent outwardly to resiliently engage the inner sides of the upstanding arms 32 and 34 of the common bracket contact 26, and a pin 108 engaged in apertures in the bracket arms 32 and 34 passes through these wiper'arms 106 to mount the auxiliary arm for pivotal movement beneath the main contact arm 74. A contact 110 is secured to the distal end of the auxiliary contact arm, preferably being riveted to the resilient member 104 of the arm as shown. The rigid member 102 of the auxiliary contact arm has a pair of ears 112 upstanding from the arm and has a raised dimple 113 as shown particularly in FIG. 5.

In accordance with this invention, means 114 link the main and auxiliary contact arms together for common movement so that rocking motion of the main contact arm is accompanied by pivotal motion of the auxiliary contact arm. For example, the means 114 preferably comprise a rod bent into rectangular form to extend through the loop 98 and through apertures in the ears 112 of the main and auxiliary contact arms. This linkmeans spaces the linked portions of the contact arms at a definite distance from each other as will be understood.

In a preferred embodiment of this invention, the toggle actuating means 18 is pivotably mounted on the base or housing 12 for resiliently engaging the main contact arm 74. For example, an exteriorly threaded, preferably metallic bushing 116 useful in mounting the toggle switch on a control panel or the like has a flange 118 welded to the housing cover 24 and a metal bellows 120 is fitted within the bushing. A toggle supporting member 122, preferably having a flange 124 welded to the flange of the bushing 116, has a central bore 126 and an intersecting slot 128 for receiving a toggle actuating lever 130 which is pivotably connected to the supporting member by a riveted pin 132. A knob 134 is cemented or otherwise attached to the toggle actuating lever outside the switch housing 12 and a toggle block 136 preferably formed of a phenolic resin or other rigid, electrically insulating material, is cemented or otherwise attached to the toggle lever at 138 within the switch housing. A flexible rubber gasket 140 is preferably fitted within the bushing 116 around the toggle lever 130 for weather sealing the bellows 120 in sealing the switch 10 around the toggle lever.

In the illustrated two pole switch, the toggle block has two recesses 142 retaining helical coil compression springs 144, each recess also receiving a slide or plunger 146 having a bore 148 and having a roller 150 rotatably attached to the slide by a riveted pin 152. In this arrangement, as illustrated, the rollers 150 are positioned to resiliently engage the respective main contact arm 74 in the separate poles of the switch 10 and are adapted to be moved longitudinally along the main contact arms by movement of the toggle lever 130.

In a preferred construction of the switch 10, the housing liner has depending portions 154 electrically separating the terminals of the separate switch poles and has walls 156 within the housing separating the separate compartments 14 and 16 in which the switch poles are separately located. Preferably the walls 156 slidably engage a portion of the toggle block 136 as shown particularly in FIG. 4 for guiding movement of the toggle block.

The operation of the switch 10 is as follows. When the toggle actuating means 18 is in the position shown in FIGS. 1-4 of the drawings, each toggle roller 150 carried by the actuating means resiliently engages the central portion 84 of a main contact arm 74 so that the main contact arm is firmly held against the common bracket contact 26 and so that the auxiliary contact arm 100 linked to the main arm is held in a position of pivotal movement such that the contact 110 on the auxiliary arm is firmly engaged with the contact 50 fixed to the liner base for closing a first switch circuit, the force of the spring 144 loading the contact 110.

This circuit extends from the terminal stud 40 through the common bracket contact 26, to the Wiper arms 106, the resilient arm strip 104 and the contact 110 to the contact 50, the bar 62, and the terminal stud 64. As the auxiliary contact arm includes a resilient strip 104, the

contact 110 is held against the contact 51) with sufficient contact pressure to withstand vibrational forces and to maintain the first switch circuit closed without contact chatter. Further, because the toggle rollers 150 engage the main contact arm at a central depression on the arm, the toggle means is retained in the position shown in FIGS. 1-4 and cannot be moved from that position without compressing the springs 144. As will be understood a corresponding circuit is closed in the other pole of the switch 10.

When the toggle actuating lever 130 is pivoted to the position shown in FIG. 5, each toggle roller 150 is moved upwardly compressing the spring 144 so that the roller can move out of the depression formed at the center of the main contact arm. As the roller 150 moves out of this depression and moves past the location at which an ear of the contact arm engages a shoulder 70 on the bracket contact 26, the pressure resiliently exerted on the main contact arm by the roller 150, rocks the main contact arm with sharp, snap-action to the position shown in FIG. 5 of the drawings. That is, the main contact arm remains in the position shown in FIG. 3 until the toggle roller 150 passes over a ridge 160 formed on the contact arm and engages an end portion 86 of the main contact arm. At this point the main contact arm rocks rapidly to the new switch position shown in FIG. 5 so that a contact 80 carried by the main contact arm engages the additional contact 52 fixed to the liner base for closing an alternate switch circuit. The rigid member 82 then bears against the upper side of the resilient member 76 of the main contact arm means for minimizing contact bounce. Engagement of the toggle lever 130 with the supporting member flange 124 limits lateral movement of the toggle actuating means. This alternate switch circuit extends from the terminal stud 40 through the common contact 26, the wiper arm 94, the resilient strip 76 and the contact 80 to the contact 52 and a terminal stud 56. As the main contact arm 74 is rocked to the position shown in FIG. 5, the link means 114 connecting the main arm to the auxiliary contact arm causes the auxiliary contact arm to pivot on pin 108 for sharply moving the auxiliary arm contact out of engagement with the contact 50, thereby opening the first switch circuit abovedescribed. In closing the circuit between the contacts 80 and 52, the resilient mounting of the contact 80 causes the contact to engage contact 52 with a wiping action to assure good electrical engagement of the contacts. The fact that a single toggle roller serves to open one circuit while closing another circuit assures proper sequential opening and closing of the switch circuits. The fact that a single spring serves to maintain the toggle means in selected switch positions and also serves to load each pair of contacts in closing each switch circuit means that only one spring force need be overcome in operating the switch. a factor which permits easy switch operation.

As will be understood, movement of the toggle actuating lever from the position shown in FIG. 5 to the position shown in FIG. 1, opens the circuit between the contacts 80 and 52 and recloses the circuit between the switch contacts 110 and 50 with snap action. Similarly, movement of the actuating lever 130 to the right moves the toggle roller to the left into engagement with the base contact 54 as is indicated by the broken lines 162 in FIG. 5 to close another alternate switch circuit. This motion of the main contact arm also serves to reopen the circuit between the contacts 110 and 50. This other alternate circuit extends from the terminal stud 40, through the common bracket contact 26, the wiper arms 94, the resilient strip 76 and the contact 78 to the contact 54 and a terminal stud 56.

The dimple 113 on the auxiliary contact arm is adapted to engage the loop member 96 on the main contact arm when the switch closes this circuit between contacts 110 and 50 to prevent inadvertent self-locking of the switch due to excessive pivoting of the auxiliary contact arm.

In this way, the switch of this invention provides toggle actuating means movable between three alternate positions for closing any one of three alternate circuits between a common contact or terminal 26 and respective additional contacts 50, 52 and 54. Each of the switch circuits is closed between a resiliently mounted movable contact and a fixed base contact so that the switch contacts are engaged with each other with minimum bounce, with a wiping action for good electrical engagement, and with firm contact pressure for vibration resistance. In each switch pole, the engagement of a toggle roller 150 as biased by a single spring 144 serves to maintain the position of the toggle and to hold pairs of switch contacts together with substantially equal contact pressure. This means that the switch contacts can be held firmly together but the switch is still easy to operate. Further, operating of the single toggle actuating means serves to close a corresponding circuit in each separate pole of the switch. Each switch circuit is also opened and closed with snap action to minimize contact arcing and wear.

An alternate arrangement of contacts in each switch pole is illustrated in FIG. 6. That is, where the mounting space available for the switch makes a longer but less wide switch housing desirable, the bar 62 connecting the contact 50 to the terminal stud 66 in the switch embodiment illustrated in FIGS. 1-5 can be replaced by a bar 62a as shown in FIG. 6. This bar 62a is secured at one end to a contact 50a and at its other end to a stud 66a, this contact and stud being comparable to the contact 50 and stud 66 previously described. In this alternate embodiment of FIG. 6, the bar 62a is apertured as at 162 to fit around the terminal stud 54a comparable to the stud 54 in the embodiment of FIGS. 1-5. In this embodiment, the walls 156 on the housing liner can be altered in any conventional manner to provide guidance for movement of the switch toggle block.

It should be understood that although particular embodiments of the switch of this invention have been described by way of illustration, this invention includes all modifications and equivalents of the illustrated embodiments which fall within the scope of the appended claims.

We claim:

1. A toggle switch for alternately closing one of three circuits between a common contact and respective additional contacts comprising an electrically insulating base, a common electrically-conductive U-shaped bracket contact having its central portion secured to said base and its two arms upstanding from said base, three additional electrically-conductive contacts mounted on said base in spaced relation to each other and to said common contact, electrically-conductive main contact arm means supported on said bracket arms for rocking motion between said bracket arms, electrically-conductive auxiliary contact arm means having one end disposed between and pivotally connected to said bracket arms, means linking said main and auxiliary contact arm means for movement together, and toggle means resiliently engaging a portion of said main contact arm means to hold said auxiliary contact arm means in engagement with one of said additional contacts mounted on said base for closing a first switch circuit, said toggle means being movable to engage two alternate portions of said main contact arm means to rock said main contact arm means into engagement with respective additional contacts mounted on said base for closing alternate switch circuits and to pivot said auxiliary contact arm means out of engagement with said one additional contact for opening said first switch circuit.

2. A toggle switch as set forth in claim 1 wherein said contact arm means have electrically-conductive wiper arm means resiliently engaging said common bracket contact for maintaining good electrical connection between said contact arm means and said common contact in all positions of movement of said contact arm means.

3. A toggle switch as set forth in claim 1 wherein each bracket arm has two shoulders at the upstanding end thereof and has a spacer portion separating said shoulders, and wherein said main contact arm means has a pair of ears at each side thereof resting on respective shoulders on said bracket to locate said main contact arm means on said bracket and to support said main contact arm means for rocking motion between said bracket arms.

4. A toggle switch as set forth in claim 3 wherein said main contact arm means embodies a rigid member having said ears thereon and a resilient electrically-conductive member secured to said rigid member, said resilient member having a contact secured at each end thereof for engagement with a respective additional contact mounted on said base.

5. A toggle switch as set forth in claim 4 wherein said auxiliary contact arm means embodies a rigid member secured at one end to an electrically conductive resilient member, the opposite end of said resilient member being disposed between said common bracket arms and pivotably connected at each side of said opposite end to respective common bracket arms, said resilient member having a contact secured to its distal end for engagement with said one additional contact mounted on said base.

6. A toggle switch as set forth in claim 5 wherein said link means comprise a link pivotably connected at respective opposite ends to said main and auxiliary contact arm means so that rocking motion of said main contact arm means is accompanied by pivotal motion of said auxiliary contact arm means.

7. A toggle switch as set forth in claim 4 wherein said rigid member has a central portion forming a depression between said common bracket arms and said toggle means engages said central portion for closing said first switch circuit, said rigid member having end portions angularly disposed relative to said central portion to be engaged by said toggle means for closing said alternate switch circuits.

8. A toggle switch for alternately closing one of three circuits between a common contact and respective additional contacts comprising an electrically-insulating base, a common electrically-conductive U-shaped bracket contact having its central portion secured to said base and its two arms upstanding from said base, each of said bracket arms having two shoulders at the upstanding end thereof separated by a spacer portion, three additional electrically-conductive contacts mounted on said base in spaced relation to each other and to said common contact, a main contact arm embodying a rigid member secured to a central portion of an electrically-conductive resilient member, said rigid member having a pair of ears on each side thereof resting on respective shoulders of said bracket arms supporting said main contact arm for rocking motion between said bracket arms, said rigid member having a central portion forming a central depression and end portions angularly disposed relative to said central portion of said rigid member, said resilient member having a contact secured at each end thereof and having electrically-conductive wiper arm means slidably engaging said common bracket arms, an auxiliary contact arm embodying a rigid member secured at one end to an end of an electrically conductive resilient member and overlying part of said resilient member, said auxiliary arm having an end of said resilient member disposed between and pivotably connected to said common bracket arms and having wiper arm means slidably engaging said common bracket arms, said resilient member of said auxiliary arm having a contact at the distal end thereof, a link pivotably connected at respective opposite ends to said main and auxiliary contact arms, and toggle means pivotably mounted on said base, said toggle means resiliently engaging said central portion of said main contact arm to hold said auxiliary arm contact in engagement with one of said additional contacts mounted on said base for closing a first switch circuit, said toggle means being movable to alternately engage said angularly disposed portions of said main contact arm to rock said main arm contacts into engagement with respective additional contacts mounted on said base for closing alternate switch circuits and to pivot said auxiliary arm contact out of en gagement with said one additional contact for opening said first switch circuit.

9. A multi-pole toggle switch for alternately closing one of three circuits in each pole between a common contact and respective additional contacts comprising, an electrically insulating base, a common electrically-conductive U-shaped bracket contact in each pole having its central portion secured to said base and its two arms upstanding from said base, three additional electrically-conductive contacts in each pole mounted in said base in spaced relation to each other and to said common contact, electrically-conductive main contact arm means in each pole supported on said bracket arms for rocking motion between said bracket arms, electrically-conductive auxiliary contact arm means in each pole having one end disposed between and pivotably connected to said bracket arms, means linking said main and auxiliary contact arm means in each pole for movement together, and a toggle means resiliently engaging a portion of said main contact arm means, each pole to hold said auxiliary contact arm means in engagement with one of said additional contacts in each pole for closing a first switch circuit in each pole, said toggle means being movable to engage two alternate portions of said main contact arm means in each pole to rock said main contact arm means into engagement with respective additional contacts in each pole for closing alternate switch contacts in each pole and to pivot said auxiliary contact arm means out of engagement with said one additional contact in each pole for opening said first switch circuit in each pole.

References Cited UNITED STATES PATENTS 2,849,549 8/1958 Elliott. 2,857,486 10/1958 Brooks. 2,961,519 11/1960 Sandowsky et al. 200-68 3,022,394 2/1962 Grotz 20068 ROBERT K. SCHAEFER, Primary Examiner.

DAVID SMITH, JR., Assistant Examiner. 

